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作者：ghost 来源：CSDN 2007年9月24日
关键字： ghost NHibernate many-to-many
通过进一步学习Nhibernate基础知识，掌握用Nhiberate实现多对多的业务逻辑
开发环境: windows 2003,Visual studio .Net 2005,Sql server 2005 developer edition
前期准备: 学习上两篇单表操作和many-to-one篇
3．对上篇文章的部分解释
1)bag节点:用于定义System.Collection.IList类型的集合元素。
|
属性 |
用法 |
举例 |
|
name |
映射的属性（必须） |
name=”SalaryList” |
|
table |
映射的数据表(可选) | table=”Salary” |
| lazy | 延迟加载(可选) | Lazy=true|false |
| cascade | 指示级联操作方式（可选） | Cascade=all |
| inverse | 关联由谁负责维护 | Inverse=”true” |
当lazy=”true”，父类初始化的时候不会自动加载子类集合
Cascade为级联操作方式，包括：
| 属性 | 用法说明 |
| none | 默认值，不进行级联操作 |
| save-update | save和update级联 |
| delete | 删除级联 |
| delete-orphan | 删除不相关的父对象的子对象 |
| all | save/update/delete级联 |
| all-delete-orphan | all+delete-arphan |
当inverse=”true”的时候代表由子类维护级联关系。这时候如果只往父类中添加子类，但不设定子类的父类，是不能保存子类的。 还是用户系统，1个用户职员隶属于多个部门，同时1个部门有多个不同的职员
用户和部门之间的数据关系图为:
5. 实现步骤:
1)User.cs
using System;using System.Collections.Generic;using System.Text;namespace NhibernateSample1{ public class User { private int _id; private string _name; private string _pwd; private System.Collections.IList _departmentsList; /**//// <summary> /// 编号 /// </summary> public virtual int Id { get { return _id; } set { _id = value; } } /**//// <summary> /// 名称 /// </summary> public virtual string Name { get { return _name; } set { _name = value; } } /**//// <summary> /// 密码 /// </summary> public virtual string Pwd { get { return _pwd; } set { _pwd = value; } } /**//// <summary> /// 工资列表 /// </summary> public System.Collections.IList DepartmentsList { get { return _departmentsList; } set { _departmentsList = value; } } }}
2)User.hbm.xml
<?xml version="1.0" encoding="utf-8" ?><hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <class name="NhibernateSample1.User,NhibernateSample1" table="Users" lazy="false"> <id name="Id" column="Id" unsaved-value="0"> <generator class="native" /> </id> <property name="Name" column="Name" type="string" length="64" not-null="true" unique="true"></property> <property name="Pwd" column="Pwd" type="string" length="64" not-null="true"></property> <bag name="DepartmentsList" table="Users_Departments" inverse="true" lazy="false" cascade="all"> <key column="Id"/> <many-to-many class="NhibernateSample1.Departments,NhibernateSample1" column="DepID"></many-to-many> </bag> </class></hibernate-mapping>
3) Departments.cs
using System;using System.Collections.Generic;using System.Text;using System.Collections;namespace NhibernateSample1{ public class Departments { int _depID; string _name; IList _usersList= new ArrayList(); public virtual int DepID { get { return _depID; } set { _depID = value; } } public virtual string Name { get { return _name; } set { _name = value; } } public virtual IList UsersList { get { return _usersList; } set { _usersList = value; } } }}
4) Departments.hbm.xml
<?xml version="1.0" encoding="utf-8" ?><hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <class name="NhibernateSample1.Departments,NhibernateSample1" table="Departments" lazy="false"> <id name="DepID" column="DepID" unsaved-value="0"> <generator class="native" /> </id> <property name="Name" column="Name" type="string" length="64" not-null="true" unique="true"></property> <bag name="UsersList" table="Users_Departments" lazy="true" > <key column="DepID"/> <many-to-many class="NhibernateSample1.User,NhibernateSample1" column="Id"></many-to-many> </bag> </class></hibernate-mapping>
5) 数据操作类
using System;using System.Collections.Generic;using System.Text;using System.Collections;using NHibernate;using NHibernate.Cfg;using NHibernate.Tool.hbm2ddl;namespace NhibernateSample1{ public class UserDepartmentFixure { private ISessionFactory _sessions; public void Configure() { Configuration cfg = GetConfiguration(); _sessions = cfg.BuildSessionFactory(); } Configuration GetConfiguration() { string cfgPath = @"E:\my project\nhibernate study\simle 1\NHibernateStudy1\NhibernateSample1\hibernate.cfg.xml"; Configuration cfg = new Configuration().Configure(cfgPath); return cfg; } public void ExportTables() { Configuration cfg = GetConfiguration(); new SchemaExport(cfg).Create(true, true); } public User CreateUser(String name,string pwd) { User u = new User(); u.Name = name; u.Pwd = pwd; u.DepartmentsList = new ArrayList(); ISession session = _sessions.OpenSession(); ITransaction tx = null; try { tx = session.BeginTransaction(); session.Save(u); tx.Commit(); } catch (HibernateException e) { if (tx != null) tx.Rollback(); throw e; } finally { session.Close(); } return u; } public Departments CreateDepartments(User u, string name) { Departments item = new Departments(); item.Name=name; u.DepartmentsList.Add(item); item.UsersList.Add(u); ISession session = _sessions.OpenSession(); ITransaction tx = null; try { tx = session.BeginTransaction(); session.Save(item); tx.Commit(); } catch (HibernateException e) { if (tx != null) tx.Rollback(); throw e; } finally { session.Close(); } return item; } public Departments GetDepartments(int depID) { ISession session = _sessions.OpenSession(); ITransaction tx = null; try { tx = session.BeginTransaction(); Departments item = (Departments)session.Load(typeof(Departments), depID); tx.Commit(); return item; } catch (HibernateException e) { if (tx != null) tx.Rollback(); return null; } finally { session.Close(); } return null; } public User GetUser(int uid) { ISession session = _sessions.OpenSession(); ITransaction tx = null; try { tx = session.BeginTransaction(); User item = (User)session.Load(typeof(User), uid); tx.Commit(); return item; } catch (HibernateException e) { if (tx != null) tx.Rollback(); return null; } finally { session.Close(); } return null; } public void Delete(int uid) { ISession session = _sessions.OpenSession(); ITransaction tx = null; try { tx = session.BeginTransaction(); Departments item = session.Load(typeof(Departments), uid) as Departments; session.Delete(item); tx.Commit(); } catch (HibernateException e) { if (tx != null) tx.Rollback(); throw e; } finally { session.Close(); } } }}
6)单元测试类
using System;using System.Text;using System.Collections.Generic;using Microsoft.VisualStudio.TestTools.UnitTesting;using NhibernateSample1;namespace TestProject1{ /**//// <summary> /// UnitTest1 的摘要说明 /// </summary> [TestClass] public class UnitTest1 { public UnitTest1() { // // TODO: 在此处添加构造函数逻辑 // } NhibernateSample1.UserDepartmentFixure usf = new UserDepartmentFixure(); 其他测试属性#region 其他测试属性 // // 您可以在编写测试时使用下列其他属性: // // 在运行类中的第一个测试之前使用 ClassInitialize 运行代码 // [ClassInitialize()] // public static void MyClassInitialize(TestContext testContext) { } // // 在类中的所有测试都已运行之后使用 ClassCleanup 运行代码 // [ClassCleanup()] // public static void MyClassCleanup() { } // // 在运行每个测试之前使用 TestInitialize 运行代码 // [TestInitialize()] // public void MyTestInitialize() { } // // 在运行每个测试之后使用 TestCleanup 运行代码 // [TestCleanup()] // public void MyTestCleanup() { } // #endregion [TestMethod] public void Test1() { usf.Configure(); usf.ExportTables(); User u = usf.CreateUser(Guid.NewGuid().ToString(), "ds"); Assert.IsTrue(u.Id>0); Departments s = usf.CreateDepartments(u, "政治部"); Assert.IsTrue(s.DepID > 0); Departments s1 = usf.CreateDepartments(u, "事业部"); Assert.IsTrue(s1.DepID > 0); usf.Delete(s1.DepID); s1 = usf.GetDepartments(s1.DepID); Assert.IsNull(s1); User u1 = usf.GetUser(1); Assert.IsTrue(u1.DepartmentsList.Count>0); } }}
到现在为止，终于更加体会到nhibernate的强大了。继续努力，fight!
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